LAS VEGAS – Jabin Chollet overwhelmed Michael Portales in the second round of their junior welterweight fight Saturday afternoon at T-Mobile Arena.

Chollet, a 21-year-old San Diego native, landed a left uppercut and a subsequent right hand that staggered Portales in the second round. Referee Robert Hoyle then stepped in to prevent Portales from taking unnecessary punishment and halted the action at 1:58 of the second round on the non-televised portion of the Errol Spence Jr.-Terence Crawford undercard.

The hard-hitting Chollet upped his record to 8-0 and recorded his seventh knockout. Portales (3-2-1, 1 KO), of Hayward, California, has lost two of his past three bouts by technical knockout.

Earlier Saturday, Demler Zamora scored an easy eight-round shutout victory over Nikolai Buzolin to remain unbeaten.

The 20-year-old southpaw remained in control of their nondescript lightweight fight from start to finish. All three judges – Guido Cavalleri, Dave Moretti and Don Trella – scored Zamora an 80-72 winner over Buzolin.

Zamora improved to 12-0 (9 KOs). Brooklyn’s Buzolin (9-5-1, 5 KOs) has lost two of his past three fights.

In the bout before Zamora’s win, DeShawn Prather became the first fighter to defeat Kevin Ventura by narrowly winning a six-round unanimous decision.

Prather’s knockdown of Ventura during the fifth round was the only thing that separated them on the scorecards. Judges Eric Cheek, Max De Luca and Benoit Roussel all scored three rounds apiece for Prather and Ventura, but each judge credited Prather with a 57-56 win due to the abovementioned knockdown.

Kansas City’s Prather (16-1, 2 KOs) has won 15 fights in a row. Omaha’s Ventura slipped to 11-1 (8 KOs).

In the first fight on the undercard Saturday, featherweight prospect Justin Viloria stopped Pedro Borgaro in the fourth round of their scheduled six-rounder.

Viloria (3-0, 3 KOs), an 18-year-old southpaw from Whittier, California, dropped Borgaro in the second round and basically battered him until referee Robert Hoyle had seen enough. Hoyle stepped in to save a defenseless Borgaro and stopped the action 41 seconds into the fourth round.

Borgaro (5-1, 3 KOs) was still on his feet when their fight ended.

Viloria is a nephew of former flyweight and junior flyweight champ Brian Viloria.

Keith Idec is a senior writer/columnist for He can be reached on Twitter @Idecboxing.